Foster's old-style unionism left chasm with McGuinness that could not be bridged
In his three years as Deputy First Minister Martin McGuinness served alongside three DUP first ministers. With one his relationship was astonishingly good, with another it was generally reasonable, while with the third - Arlene Foster - it was frankly terrible.
He got on with Ian Paisley amazingly well, despite the fact that the DUP leader had spent a lifetime fiercely opposing the IRA and Sinn Féin, while McGuinness had built a reputation as a flinty IRA commander.
The two left most of their long-time reputations behind them, replacing old animosities with a new willingness to compromise, both politically and personally. After Paisley's retirement they kept in touch; it is said the two men prayed together, with McGuinness saying on Paisley's death that their friendship existed "until the day he died."